import java.sql.Array;
import java.util.Scanner;

public class Test {
    public static String findOneEle2(String str){
        StringBuilder sb=new StringBuilder();
        int[] arr=new int[58];
        for (int i = 0; i < str.length(); i++) {
            char ch=str.charAt(i);
            if(arr[ch-65]==0){
                sb.append(ch);
                arr[ch-65]=1;
            }
        }
        return sb.toString();
    }
    public static String findOneEle1(String str){
        StringBuilder sb=new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            char ch=str.charAt(i);
            if(!sb.toString().contains(ch+"")){
                sb.append(ch);
            }
        }
        return sb.toString();
    }
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        while(sc.hasNextLine()){
            String str=sc.nextLine();
            String ret=findOneEle2(str);
            System.out.println(ret);
        }


    }
}
